title: Cytotoxicity of ophthalmic solutions with and without preservatives to human corneal endothelial cells, epithelial cells and conjunctival epithelial cells.
abstract: OBJECTIVE
  The cytotoxicity of a range of commercial ophthalmic solutions in the presence and absence of preservatives was assessed in human corneal endothelial cells (HCECs), corneal epithelia and conjunctival epithelia using in vitro techniques.
  
  
  METHODS
  Cell survival was measured using the WST-1 assay for endothelial cells and the MTT assay for epithelial cells. Commercially available timolol, carteolol, cromoglicate, diclofenac, bromfenac and hyaluronic acid ophthalmic solutions were assessed for cytotoxicity in the presence and absence of preservatives. The preservatives benzalkonium, chlorobutanol and polysorbate were also tested. The survival of cells exposed to test ophthalmic solutions was expressed as a percentage of cell survival in the control solution (distilled water added to media) after 48 h exposure.
  
  
  RESULTS
  HCEC survival was 20-30% in ophthalmic solutions diluted 10-fold. The survival of HCEC was significantly greater in all solutions in the absence of preservative than in the presence of preservative. The survival of corneal and conjunctival epithelia was consistent with that of HCECs for all test ophthalmic solutions. The preservatives polysorbate and benzalkonium were highly cytotoxic with cell survival decreasing to 20% at the concentration estimated in commercial ophthalmic solutions. By comparison, the survival of cells exposed to chlorobutanol was 80% or greater.
  
  
  CONCLUSIONS
  The cytotoxicity of ophthalmic solutions to HCEC, corneal epithelia and conjunctival epithelia decreased in the absence of preservative.
authors.affiliation: Department of Ophthalmology, Fujigaoka Hospital, Showa University School of Medicine, Aobaku Yokohama, Kanagawa, Japan. mayaki@olive.ocn.ne.jp
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ayaki
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yaguchi
authors.forename: Atsuo
authors.initials: A
authors.lastname: Iwasawa
authors.forename: Ryohei
authors.initials: R
authors.lastname: Koide
mesh_terms: D001548:Benzalkonium Compounds / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002724:Chlorobutanol / Q000633:toxicity; D003228:Conjunctiva / Q000166:cytology / Q000187:drug effects*; D004338:Drug Combinations; D004728:Endothelium, Corneal / Q000166:cytology / Q000187:drug effects*; D004847:Epithelial Cells / Q000187:drug effects; D019573:Epithelium, Corneal / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D009883:Ophthalmic Solutions / Q000633:toxicity*; D011136:Polysorbates / Q000633:toxicity; D011310:Preservatives, Pharmaceutical / Q000633:toxicity*
chemical_list: D001548:Benzalkonium Compounds; D004338:Drug Combinations; D009883:Ophthalmic Solutions; D011136:Polysorbates; D011310:Preservatives, Pharmaceutical; D002724:Chlorobutanol